Personally, I think tatoos are great things, but getting one about the wrestling industry would be a terrible idea because it is always changing.
If however you are serious, I guess the one suggestion I would have would be the World Title of the first company you watched (for me that would be the NWA Title)...that or a silhouette of someone doing an elbow drop (no one receiving it, just a picture perfect elbow drop). Or The Four Horsemen Fingers, or maybe if you were a DX fan a tatoo of some hands doing the crotch chop, or the Kliq/nWo Wolfpac hand gesture, or maybe just a tatoo of WrestleMania, since pretty much everyone can agree WrestleMania is the SuperBowl for any wrestler.
Or you could ask Triple A to pay you $500 to tatoo TPWW.net across your chest.